Respiratory minute volume
(or minute ventilation
, or flow of gas
) is the volume
which can be inhaled
(inhaled minute volume) or exhaled
(exhaled minute volume) from a person's lungs
in one minute. This is normally registered when a person has a ventilator
supporting the person's breathing
due to a sickness or injury
Minute volume is calculated by taking the tidal volume and multiplying the respiratory rate (the number of breaths per minute a person is taking). The higher the minute volume the more carbon dioxide (CO2) the person is releasing, the converse is the lower the minute volume the lower the amount of carbon dioxide the person is releasing. For example a person who is hyperventilating would have an increased minute volume.
A normal minute volume would be 5–8 liters per minute.
The symbol used to represent minute volume is or MV.
Relationship to other Physiological Rates
Minute volume is closely related to both alveolar ventilation and dead space ventilation. That is;
Where is alveolar ventilation, and represents dead space ventilation